1. Field of the Invention
This invention directs itself to fastener ejecting guns for securement of a workpiece to a substrate. In particular, this invention directs itself to a handle assembly for supporting a pair of fastener ejecting guns and actuating both to simultaneously drivingly deliver a pair of fasteners in two different directions. Still further, this invention directs itself to a tool having a handle disposed between a pair of supporting members between which are coupled a pair of fastener ejecting guns. More in particular, this invention pertains to a tool having a trigger assembly pivotally coupled to a handle assembly for substantially simultaneously actuating each of a pair of fastener ejecting guns responsive to pivotal displacement of the trigger actuating assembly. Further, this invention directs itself to a tool having an air distribution assembly incorporated into a rear support member thereof.
2. Prior Art
Tools for applying a corner bead to a dry wall are well known in the art. The best prior art known to Applicant include U.S. Pat. Nos. 5,333,483; 4,989,438; 4,288,016; 4,738,071; 5,267,391; 5,320,268; 4,610,381; 4,670,957; 4,593,443; 4,670,957; 2,944,262; 2,859,445; 3,130,890; and, 969,471.
Some prior art systems, such as that shown in U.S. Pat. No. 4,989,438, are directed to a system for driving a pair of fasteners into a protective corner strip. Such systems utilize a pair of striking elements formed as part of a toggle mechanism which is moved responsive to displacement of a reciprocated shaft of a powered actuator. However, in addition to the complex mechanics formed by the linkage between the striking elements and the reciprocated shaft, the driving force which is applied by the reciprocated shaft must be divided between the pair of striking members, requiring the user to support the tool against a very large reaction force. Whereas in the present invention the two actuators are disposed in an angular relationship such that a portion of the reaction force of one actuator is opposed by the reaction force of the other. Thus, for the present invention, where the actuators are disposed in an orthogonal relationship, the user will only be exposed to half the total reaction force, which is therefore equivalent to the forces generated by a single actuator applying a single fastener.
In other prior art systems, such as that disclosed by U.S. Pat. No. 4,288,016, there is provided a tool for applying plastic corner bead utilizing a pair of mechanically operated staple guns. The staple guns are pivotally supported about an axis transverse to the longitudinal axis of each of the staple guns with a displaceable handle configured to displace the operating levers of each of the staple guns as the handle lever is inwardly displaced. This system also provides for a pair of transversely spaced abutment members having notches formed therein to act as a guide for applying the tool. A tubular handle is disposed between one abutment and the pair of staple guns, disposed orthogonally with respect to the actuating handle. Thus, this system is difficult to support and operate, requiring two hands to operate.